andyzinsser

// request Game Center verification data for localPlayer from apple
- (void)authenticateGameCenterPlayer:(GKLocalPlayer *)localPlayer
{
    [localPlayer generateIdentityVerificationSignatureWithCompletionHandler:^(NSURL *publicKeyUrl, NSData *signature, NSData *salt, uint64_t timestamp, NSError *error) {
        if (error) {
            NSLog(@"ERROR: %@", error);
        }
        else {
            // package data to be sent to server for verification
            NSDictionary *params = @{@"publicKeyUrl": publicKeyUrl,